cppcheck/test/testvaarg.cpp

/*
 * Cppcheck - A tool for static C/C++ code analysis
 * Copyright (C) 2007-2014 Daniel Marjamäki and Cppcheck team.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "testsuite.h"
#include "checkvaarg.h"
#include "tokenize.h"
#include <sstream>

extern std::ostringstream errout;

class TestVaarg : public TestFixture {
public:
    TestVaarg() : TestFixture("TestVaarg") {}

private:
    void check(const char code[]) {
        // Clear the error buffer..
        errout.str("");

        Settings settings;
        settings.addEnabled("warning");

        // Tokenize..
        Tokenizer tokenizer(&settings, this);
        std::istringstream istr(code);
        tokenizer.tokenize(istr, "test.cpp");

        // Check..
        CheckVaarg checkVaarg(&tokenizer, &settings, this);
        checkVaarg.runSimplifiedChecks(&tokenizer, &settings, this);
    }

    void run() {
        TEST_CASE(wrongParameterTo_va_start);
        TEST_CASE(referenceAs_va_start);
        TEST_CASE(va_end_missing);
        TEST_CASE(va_list_usedBeforeStarted);
        TEST_CASE(va_start_subsequentCalls);
    }

    void wrongParameterTo_va_start() {
        check("void Format(char* szFormat, char* szBuffer, size_t nSize, ...) {\n"
              "    va_list arg_ptr;\n"
              "    va_start(arg_ptr, szFormat);\n"
              "    va_end(arg_ptr);\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3]: (warning) 'szFormat' given to va_start() is not last named argument of the function. Did you intend to pass 'nSize'?\n", errout.str());

        check("void Format(char* szFormat, char* szBuffer, size_t nSize, ...) {\n"
              "    va_list arg_ptr;\n"
              "    va_start(arg_ptr, szBuffer);\n"
              "    va_end(arg_ptr);\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3]: (warning) 'szBuffer' given to va_start() is not last named argument of the function. Did you intend to pass 'nSize'?\n", errout.str());

        check("void Format(char* szFormat, char* szBuffer, size_t nSize, ...) {\n"
              "    va_list arg_ptr;\n"
              "    va_start(arg_ptr, nSize);\n"
              "    va_end(arg_ptr);\n"
              "}");
        ASSERT_EQUALS("", errout.str());

        check("int main(int argc, char *argv[]) {\n"
              "    long(^addthem)(const char *, ...) = ^long(const char *format, ...) {\n"
              "        va_list argp;\n"
              "        va_start(argp, format);\n"
              "        c = va_arg(argp, int);\n"
              "    };\n"
              "}"); // Don't crash (#6032)
        ASSERT_EQUALS("[test.cpp:6]: (error) va_list 'argp' was opened but not closed by va_end().\n", errout.str());

        check("void Format(char* szFormat, char* szBuffer, size_t nSize, ...) {\n"
              "    va_list arg_ptr;\n"
              "    va_start(arg_ptr);\n"
              "    va_end(arg_ptr);\n"
              "}"); // Don't crash if less than expected arguments are given.
        ASSERT_EQUALS("", errout.str());
    }

    void referenceAs_va_start() {
        check("void Format(char* szFormat, char (&szBuffer)[_Size], ...) {\n"
              "    va_list arg_ptr;\n"
              "    va_start(arg_ptr, szBuffer);\n"
              "    va_end(arg_ptr);\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3]: (error) Using reference 'szBuffer' as parameter for va_start() results in undefined behaviour.\n", errout.str());

        check("void Format(char* szFormat, char (*szBuffer)[_Size], ...) {\n"
              "    va_list arg_ptr;\n"
              "    va_start(arg_ptr, szBuffer);\n"
              "    va_end(arg_ptr);\n"
              "}");
        ASSERT_EQUALS("", errout.str());
    }

    void va_end_missing() {
        check("void Format(char* szFormat, char (*szBuffer)[_Size], ...) {\n"
              "    va_list arg_ptr;\n"
              "    va_start(arg_ptr, szBuffer);\n"
              "    va_end(arg_ptr);\n"
              "}");
        ASSERT_EQUALS("", errout.str());

        check("void Format(char* szFormat, char (*szBuffer)[_Size], ...) {\n"
              "    va_list arg_ptr;\n"
              "    va_start(arg_ptr, szBuffer);\n"
              "}");
        ASSERT_EQUALS("[test.cpp:4]: (error) va_list 'arg_ptr' was opened but not closed by va_end().\n", errout.str());

        check("void Format(char* szFormat, char (*szBuffer)[_Size], ...) {\n"
              "    va_list arg_ptr;\n"
              "    va_start(arg_ptr, szBuffer);\n"
              "    if(sth) return;\n"
              "    va_end(arg_ptr);\n"
              "}");
        ASSERT_EQUALS("[test.cpp:4]: (error) va_list 'arg_ptr' was opened but not closed by va_end().\n", errout.str());
    }

    void va_list_usedBeforeStarted() {
        check("void Format(char* szFormat, char (*szBuffer)[_Size], ...) {\n"
              "    va_list arg_ptr;\n"
              "    return va_arg(arg_ptr, float);\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3]: (error) va_list 'arg_ptr' used before va_start() was called.\n", errout.str());

        check("void Format(char* szFormat, char (*szBuffer)[_Size], ...) {\n"
              "    va_list arg_ptr;\n"
              "    foo(arg_ptr);\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3]: (error) va_list 'arg_ptr' used before va_start() was called.\n", errout.str());

        check("void Format(char* szFormat, char (*szBuffer)[_Size], ...) {\n"
              "    va_list arg_ptr;\n"
              "    va_copy(f, arg_ptr);\n"
              "}");
        ASSERT_EQUALS("[test.cpp:3]: (error) va_list 'arg_ptr' used before va_start() was called.\n", errout.str());

        check("void Format(char* szFormat, char (*szBuffer)[_Size], ...) {\n"
              "    va_list arg_ptr;\n"
              "    va_start(arg_ptr, szBuffer);\n"
              "    va_end(arg_ptr);\n"
              "    return va_arg(arg_ptr, float);\n"
              "}");
        ASSERT_EQUALS("[test.cpp:5]: (error) va_list 'arg_ptr' used before va_start() was called.\n", errout.str());

        check("void Format(char* szFormat, char (*szBuffer)[_Size], ...) {\n"
              "    va_list arg_ptr;\n"
              "    va_start(arg_ptr, szBuffer);\n"
              "    va_end(arg_ptr);\n"
              "    va_start(arg_ptr, szBuffer);\n"
              "    foo(va_arg(arg_ptr, float));\n"
              "    va_end(arg_ptr);\n"
              "}");
        ASSERT_EQUALS("", errout.str());
    }

    void va_start_subsequentCalls() {
        check("void Format(char* szFormat, char (*szBuffer)[_Size], ...) {\n"
              "    va_list arg_ptr;\n"
              "    va_start(arg_ptr, szBuffer);\n"
              "    va_start(arg_ptr, szBuffer);\n"
              "    va_end(arg_ptr);\n"
              "}");
        ASSERT_EQUALS("[test.cpp:4]: (error) va_start() or va_copy() called subsequently on 'arg_ptr' without va_end() inbetween.\n", errout.str());

        check("void Format(char* szFormat, char (*szBuffer)[_Size], ...) {\n"
              "    va_list vl1;\n"
              "    va_start(vl1, szBuffer);\n"
              "    va_copy(vl1, vl1);\n"
              "    va_end(vl1);\n"
              "}");
        ASSERT_EQUALS("[test.cpp:4]: (error) va_start() or va_copy() called subsequently on 'vl1' without va_end() inbetween.\n", errout.str());

        check("void Format(char* szFormat, char (*szBuffer)[_Size], ...) {\n"
              "    va_list arg_ptr;\n"
              "    va_start(arg_ptr, szBuffer);\n"
              "    va_end(arg_ptr);\n"
              "    va_start(arg_ptr, szBuffer);\n"
              "    va_end(arg_ptr);\n"
              "}");
        ASSERT_EQUALS("", errout.str());
    }
};

REGISTER_TEST(TestVaarg)